From the Rheumatology Unit, First Department of Internal Medicine, Joint Academic Rheumatology Program, School of Medicine, National and Kapodistrian University of Athens, Athens,
Greece; US National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, Maryland,
USA.

Abstract

Methods. We assessed quality using the Newcastle-Ottawa scale for observational studies, and the Cochrane Collaboration’s risk-of-bias tool for trials.

Results. In observational studies, description of enrollment criteria was high but decreased over time. Adequacy of followup was low but improved. Inception cohorts and community-based studies were uncommon. Trials had low risk of bias in blinding and selective outcome reporting but most had unclear risks in sequence generation and allocation concealment.

Conclusion. Methodological quality was mixed, with limited improvement over time.